WEEKEND COMPETITION QUIZ O level Science 19th of November 2022

Which of the statements about energy conversion is true?

Potential energy and Kinetic energy are type of ?.

Which of the following is a 'CONDENSATION POLYMERISATION' type of reaction?

Which of the following chemical reagents and reaction conditions is used in to 'breakdown protein into amino acids'?

A sound wave travel through air at a speed of 330m/s. if the frequency of the wave is 20Hz, the wavelength is?

The wave property that makes it possible for sound to be heard round a bend is ?.

Zener diode is used for

Give the name of materials which contain lots of free electrons.

A series circuit consists of three resistors. Two resistors are 1.4 k each. The total resistance is 12 k. The value of the third resistor

A block A of mass m1 is released from top of smooth inclined plane and it slides down the plane. Another block of mass m2 such that m2 > m1is dropped from the same point and falls vertically downwards. Which one of the following statements will be true if the friction offered by air is negligible?

A 6 kg object is subject to three forces

F1 = 20i + 30j N
F2 = 8i - 50j N
F3 = 2i + 2j N

What is the acceleration of object

There are two statements
Statement A Newton’s first law in valid from the pilot in an aircraft which is taking off
Statement B Newton’s first law in valid from the observer in a train moving with constant velocity
Which of the following is correct

It is suspected that a lollipop contains traces of a poisonous green dye (boiling point 73 °C) as well as two harmless orange and red dyes (boiling points 69 °C and 73 °C respectively).

What is the best method by which the green dye may be detected?

The two statements are about the fractional distillation of crude oil. The statements may or may not be correct. They may or may not be linked.

statement 1: Fractional distillation is used to separate crude oil into useful fractions.

statement 2: The fractions with lower boiling points are found at the top of the fractionating column.

What is correct about these two statements?

Which property shows that a liquid is pure?

A hollow metal cylinder of mass 0.5kg is heated electrically by a 12W heater in a room at 15-degree Celsius cylinder temperature rises uniformly to 25 degree Celsius in 5 minutes and later becomes constant at 45 degree Celsius.

Assuming the rate of heat loss is proportional to the excess temperature over the surroundings. What is the rate of loss at 20 degree Celsius.

Which of these principles utilizes the three methods of heat transfer?

A closed metal vessel contains water at 30 degree Celsius. The vessel has a surface area of 0.5m square and a uniform thickness of 4mm. if the outside temperature is 15 degree Celsius. What is the loss per minute by conduction? (Thermal conductivity of metal, k=400Wm-1K-1

Information is given below on the reactivity of four metals Wa, Xb, Yc and Zd (NOT their real chemical symbols) ... [9f-63] ... Metal Wa does not readily react with dilute acid ... Metals Xb and Yc react slowly with acid ... Metal Zd will displace Yc from the sulphate salt solution of Yc (YcSO4(aq)) ... Metal Zd will NOT displace Xb from the chloride salt solution of Xb (XbCl2(aq)) If their reactivity order is from the most reactive (1) (2) (3) (4) to the least reactive, which metal corresponds to (2), the 2nd most reactive of the four metals?

Silvery grey iron filings are added to yellow sulphur powder in a test tube. The contents of the test tube were strongly heated until they glowed red without further heating to form a dark grey dull solid. Which statement is TRUE about the contents of the test tube in the experiment?

Which of the following is TRUE about plants?

Which is a simple test for chlorophyl?

The gases from (i) air breathed in, (ii) air breathed out, (iii) just above a lit bunsen burner flame and (iv) the gases left over after burning a candle inside an up-turned beaker where analysed. From the results quoted below, which analysis is most likely to be from the bunsen flame?

Which statement is FALSE when comparing respiration and burning a fuel?

The physical features of plants are the result of several factors. They can genetically inherit characteristics from the parent seeds or they can be due to 'environmental' factors e.g. rainfall or soil fertility. Which of the following factors applies to a plants flower colour?

Which of the following is NOT true?

A healthy diet needs a balance of many things. Which is the nutrient solvent for the chemical reactions of life?

Small amounts of minerals and vitamins are needed for good health and vitality! Which of the following dietary needs is mainly obtained from vegetables and fruit, but not meat?

Only two of the following statements accurately describe what happens in the mouth.

1 Amylase breaks down large starch molecules into smaller maltose molecules.

2 Chewing increases the surface area of food for digestion.

3 Saliva emulsifies fats into smaller droplets.

4 Teeth break up large insoluble molecules into smaller soluble molecules.

Which statements are correct?

Which statement about enzymes is essential to the lock and key hypothesis?

With respect to a network interface card, the term 10/100 refers to

Suppose that you have a the maintenance package identifies several possible field replaceable units (FRUs) that will resolve the problem. What should you do after turning the power off?

___________ ensures the integrity and security of data that are passing over a network.

The attack that focuses on capturing small packets from the network transmitted by other computers and reading the data content in search of any type of information is ____

An algorithm in encryption is called ______

S/MIME is abbreviated as __________________

Which of the following is not a strong security protocol?

It is desired to send a sequence of computer screen images over an optical fiber. The screen is 480 x 640 pixels, each pixel being 24 bits. There are 60 screen images per second. How much bandwidth is needed, and how many microns of wavelenth are needed for this band at 1.30 microns?

A field in the Ethernet message packet is

A bridge has access to which address of a station on the same network ?